Which of the following is not an assumption about an ideal gas?
a. there are no intermolecular forces of attraction.
b. the molecules do not collide with each other.
c. the molecules have no kinetic energy.
d. the molecules occupy no volume.

The Kinetic Theory of gases states that there are no inter-molecular forces and that the molecules occupy no space themselves , so A and D are out.

If we think about the remaining 2, athe molecules must have kinetic energy or they would not be moving in the container.
C- the molecules have no kinetic energy is not an assumption.

Extra Info:
Though it is not a clear assumption, we cannot stop the molecules from colliding with each other, especially if we have them trapped in a container such is the ideal gas equation. So, the ideal gas law instead states that these collisions are completely elastic: no kinetic energy is lost during collisions. This effectively means that the collisions do nothing, and we can pretend that we don't have any.
There are edits to the Ideal Gas Law to make it more realistic, which include relationships for A and D, and to some extent B, but this is very complicated!